Technical Abstract:
The yellow pigment in potato tuber flesh is caused by various carotenoids that may protect against cancer, cardiovascular disease and macular eye degeneration. This research was carried out to identify and quantify the carotenoids in 11 diploid clones of Solanum phureja-S. stenotomum that produced >5% 2n pollen and two cultivars ('Yukon Gold' and 'Superior'), and determine the relationship between the tuber yellow intensity and carotenoid content. Yellow intensity was determined by a colorimeter programmed to calculate a yellowness index. Carotenoid analyses were performed on an automated HPLC system with software for integration and quantitation with detection at 450 nm using a diode array detector. Six different carotenoids were detected: neoxanthin, violaxanthin, lutein-5,6-epoxide, lutein, zeaxanthin, and an unknown carotenoid. The total carotenoid content in the yellow-flesh diploid clones was 3 to 13 times higher than 'Yukon Gold' and 4 to 23 times higher than 'Superior'. Both total and individual carotenoids were positively correlated to the tuber yellow intensity. This suggests that selecting for more intense yellow-flesh will result in higher levels of carotenoids.